Starting in early May 2020, a new version of the StatsPlus Desktop app is being released to move on from APIs that Slack no longer allows.
After the commissioner or simmer uses the Desktop App to install the "StatsPlus v2.0" Slack App to your league workspace, anyone with a private score channel needs to invite the app to that channel.
Steps to invite:
After you've done this, if your channel was previously set up with an older version of the desktop app, it should be re-connected automatically. If not, you will need to let the commissioner know the channel name so it can be connected for you.